A minesweeping system that creates influence signatures generally must provide a large enough influence field to be effective while still minimizing the size and weight of the equipment to make the system practical from the standpoint of the platform which controls and/or tows the system. This platform may be a ship, a helicopter, a remote controlled vehicle operating above or below the water surface, or a slow moving aircraft. Minesweeping systems generally have therefore involved a trade-off of performance vis-a-vis size and weight.
Prior art systems to date have included sweep systems using open loop magnetic technology, wherein electrical current is distributed between two or more towed electrodes and the intervening seawater between the multiple electrodes is used as the electrical return. One such system, the Mk-105, utilizes a vehicle towed by a helicopter with a gas turbine power plant on the hydrofoil to generate electricity for the open loop electrodes. The Mk-105 system is powerful, but also quite large and heavy, thus requiring the hydrofoil vehicle. In general, however, the most efficient means to achieve a large magnetic field is to use the open loop means of generating the field. Thus, a ship or helicopter-hydrofoil system has generally been required for the towing. Further, such open loop systems require sufficient physical handling equipment to handle the two or more electrodes, including the appropriate deployment and retrieval of the multiple electrodes as well as maintaining the multiple electrodes separated from one another for proper functioning and to avoid tangle.
An alternative prior art sweep system, for example the SWIMS system, generates the magnetic influence field utilizing conventional dipole technology with large magnetic cores. Because of the size and weight associated with this technology, however, the magnetic field is limited by the size and weight of a practical towed body in which the system is housed.
Still further prior art minesweeping systems have involved various coils or permanent magnet solutions which also have size and weight problems that result in limited field strength.
My pending U.S. patent application Ser. No. 09/545,820 now U.S. Pat. No. 6,634,273 filed Apr. 7, 2000, discloses an open loop minesweeping system, but one which is smaller than the above-referenced prior art, lightweight, and having simplified electrode handling. A body is towed in the water by a tow cable, the body towing only one (the first) electrode behind it while still using the open loop means of generating the magnetic field. This is accomplished by having the towed body itself function as the other (second) electrode, either by making the skin of the towed body the electrode or by having removable panels on the skin of the towed body. AC input power of low amperage and high voltage is passed from the primary towing platform to the towed body, the AC power then being transformed and rectified at the towed body.